The problem of handling and short-distance conveying of predominately sacked cargoes one is faced with in farming industry is concerned with the fact that no handling means having adequate load hoisting height are available for loading transportation facilities and machines with inorganic fertilizer under field conditions. Principally, the problem consists in loading large-capacity sacks onto and unloading them from transportation facilities, as well as in charging fertilizer applicator machines using loaders with an adequate capacity available in farming industry.
Most widely known in the art is a device for gripping and hoisting filled sacks, containing a contrivance for mounting it onto a hoisting machine, and load bearing members rigidly coupled to the contrivance for mounting it onto a hoisting machine. The load bearing members carry vertical plates hinged thereto. The device under consideration incorporates also two rods arranged parallel to each other, one of which is rigidly fixed to the vertical plates at its ends, while the other rod is articulated at its ends to said vertical plates. An actuator is provided for the vertical plates to turn, said actuator being in fact at least one control arm. The contrivance for mounting the device onto a hoisting machine is essentially a clevis coupled to the load bearing members. The device in question is mounted, through the clevis, onto the load hook of the hoisting machine boom. With the help of the boom the device for gripping and handling filled sacks is brought to the throat of a filled sack. Next the sack is passed into the gap between the two rods the sack throat having been preliminarily put onto the rod rigidly fixed in the vertical plates. Then the control arm linked to the vertical plates is turned to grip the throat of the filled sack in the device, and the filled sack is hoisted and transferred to a required place. This done the sack throat is released from the device by turning the control arm in the direction opposite to that of gripping.
However, the aforementioned construction of the device for gripping and handling filled sacks makes it impossible to extend the boom reach of a hoisting machine, thus rendering impossible the loading of large-capacity sacks into the existing transportation facilities unless trestle-work is used. Inasmuch as the actuator for the vertical plates to turn is made as a manually operated control arm, an additional attendant is required for releasing the sack after its having been put onto a desired place.
Application of the aforementioned device is fraught with a danger to inflict injury upon the operator at the instant he releases the sack throat. Such a danger is due to a possibility of a premature raising of the hoisting device boom at the instant when the control arm is turned to release the sack throat.